Personal Trainer: Walking is a DS title that comes packed with two digital pedometers that sync with your DS to track how far you walk each day. It also happens to include the ability to create Mii on your DS.
Not only does the function seem to support everything found on the Wii, but it also lets you choose between six outfits. Here's a quick look at that function, one that really should be coming to the DSi on its own.
If you're not inclined to do the work, you can also import your Mii from your Wii.